Problem

When mentioning some users in a comment, some specific users cannot be searched.

• The user already has all the necessary permissions in the project and issue. Other users in the same groups as the affected user does not have this issue.
• The user cannot be searched with Display Name, but when searched with Username, it works.
• All browsers exhibit the same behavior.
• No related errors can be found in the logs.

Consider the following example, there are more than 5 users with "David" in their Display Names.

• David A (Username: 489107239)
• David E (Username: 411273870)
• David F (Username: 422239709)
• David H (Username: 438114561)
• David K (Username: 461239011)
• David Y (Username: 443019283)

Let's say you want to mention "David Y", you enter "@David" and it will only list the first 5 result (sorted alphabetically, and "David Y" is not listed). As you try to filter it down further by typing "@David Y", the user cannot be found. However, if you use the username "443019283", the user will be listed.

Cause

In the specific example above, there are two spaces between "David" and "Y". Anywhere in JIRA UI it will be shown as one space (except when you edit the user), even in the user list returned from REST API call. Therefore, it can be very difficult to notice this.

The easiest way to verify this is to edit the user in User Management where it will show the correct number of spaces, or run an SQL query in the database. For example:

select * from cwd_user where lower_display_name like '%david%';

Simply type in the correct number of spaces in between and the user should be listed. Otherwise, edit the Display Name and remove the extra space as it can be easily overlooked as mentioned above.